[R] problems with download.file() from ftp?

[Prof Brian Ripley]

First, try the example in the test file (tests/internet.R)

read.table("ftp://ftp.stats.ox.ac.uk/pub/datasets/csb/ch11b.dat")

or

download.file("ftp://ftp.stats.ox.ac.uk/pub/datasets/csb/ch11b.dat", 
"test"

That is known to work on many, many R systems.

I get the same error as you on that URL, but it looks to me that the 
site required PASV ftp, something R's download.file does not support. 
>From the detailed logs (options(internet.info=0)

<<<
230---------------------------------------------------------
230-                    Welcome To The
230-     Natural Resources Conservation Service - USDA
230-             NATIONAL WATER and CLIMATE CENTER
230---------------------------------------------------------
230-
230-    The Local Date and Time is Mon Jan 12 08:30:25 2009
230-    Current Directory is /
230-    Information Contact is: info at wcc.nrcs.usda.gov
230-    -----------------------------------------------------------
230-    Note that data files herein are at most updated once an hour.
230-
230 Guest login ok, access restrictions apply.

--
19: In download.file(url, dest) :
---

--
20: In download.file(url, dest) : Got 230
21: In download.file(url, dest) : Invalid answer to PASV

Since you are on Windows, using --internet2 (see the rw-FAQ) might 
work.

On Mon, 12 Jan 2009, zack holden wrote:

>
> Dear list,
>
> I am trying to download a text file from an ftp site using download.file().
>
> I used the following code:
> url <- "ftp://ftp.wcc.nrcs.usda.gov/data/snow/snow_course/table/history/idaho/13e19.txt"
> dest <- "c:/test/downloadtest.txt"
> download.file(url, dest)
> I get this error message, indicating that R is unable to open the connection:
> trying URL 'ftp://ftp.wcc.nrcs.usda.gov/data/snow/snow_course/table/history/idaho/13e19.txt'
> Error in download.file(url, dest) :
>  cannot open URL 'ftp://ftp.wcc.nrcs.usda.gov/data/snow/snow_course/table/history/idaho/13e19.txt'
>
> I'm sure there is a simple solution that allows R to open this connection, but after reading the "url" help file for an hour, I can't seem to find the solution. Is anyone willing to help me solve this problem?
>
> thanks in advance for any advice,
>
> Zack

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595